export default function compatibleForIE() {
  // String repeat 方法兼容性代码
  if (!String.prototype.repeat) {
    String.prototype.repeat = function(count) {
      'use strict';
      if (this == null) {
        throw new TypeError('can\'t convert ' + this + ' to object');
      }
      var str = '' + this;
      count = +count;
      if (count != count) {
        count = 0;
      }
      if (count < 0) {
        throw new RangeError('repeat count must be non-negative');
      }
      if (count == Infinity) {
        throw new RangeError('repeat count must be less than infinity');
      }
      count = Math.floor(count);
      if (str.length == 0 || count == 0) {
        return '';
      }
      // Ensuring count is a 31-bit integer allows us to heavily optimize the
      // main part. But anyway, most current (August 2014) browsers can't handle
      // strings 1 << 28 chars or longer, so:
      if (str.length * count >= 1 << 28) {
        throw new RangeError('repeat count must not overflow maximum string size');
      }
      var rpt = '';
      for (var i = 0; i < count; i++) {
        rpt += str;
      }
      return rpt;
    }
  }
}